This invention relates to electronic module housings, and particularly to housings for supporting data storage devices, such as magnetic disk drives, for use in hostile environments.
Magnetic and optical disk drives are employed as the principal memory unit for a wide variety of special and general purpose processors. These devices are characterized by a rotating disk and associated data transfer device for writing data to and reading data from the disk. Most disk drives are mounted in housings to protect the disk drive from the effects of environmental extremes, such as heat, humidity and mechanical stress, encountered in most normal operating conditions. However, these housings may not be suitable for certain environmental extremes. More particularly, certain military and space environments may subject the disk drive to extreme temperatures, pressures (or vacuum) and/or mechanical shock. For this reason, contractors supplying such units for use in these extreme conditions employed special housings to protect the disk drive from the environmental extremes that might be expected.
The data storage housings designed for extremely harsh conditions were designed to address only the specific conditions to which the data storage unit would be subjected. The reason for this is that special housings to address environmental extremes are expensive, add to the space and weight of the housed unit, and reduce the access to the unit for maintenance or salvage. Where space and weight are of concern, added volume and weight are minimized, usually by designing the housing to address only the environmental concerns to which the unit will be subjected. Ease of removal of the unit from the support platform is essential for maintenance as well as removal for salvage or destruction such as to prevent information stored on the disk drive from falling into unfriendly hands. Hence, there is a need for a housing for electronic units that protects the unit from environmental extremes, is cost effective, permits quick removal of the unit, and does not overly increase the weight or space of the unit.
Present housings designed for specific severe environmental conditions accommodate single data storage devices, such as a single disk drive system, and do not accommodate housing an array comprising a plurality of such devices. Data storage arrays are useful to meet requirements of storage redundancy, increased storage capacity and increased bandwidth. Hence, there is a need for a housing for an array of electronic units that meets the needs described above.
In a first embodiment of the invention, an array module includes a housing having a rear plate and opposing side walls defining a module chamber. A plurality of mounting locations, such as mounting slots, are provided on the side walls of the housing and in the module chamber. A plurality of electronic units, such as disk drives, have mounting features, such as mounting rails, along opposite sides and are assembled in an array to respective ones of the mounting locations on the side walls of the housing, so that the housing supports the electronic units in the module chamber. Although in the preferred embodiment the individual electronic units are fitted with rails that mate into corresponding slots, many other suitable mounting methods will be readily apparent to those of ordinary skill in the art. Each electronic unit has at least one connector, which can be a blind-mate connector, on a face that mates with one of a plurality of connectors on the housing. At least one connector, which can be a blind-mate connector on the rear plate, provides electrical connection to all of the electronic units.
An installation frame has a rear wall and opposing side walls defining an installation chamber. A connector, which can be a blind-mate connector on the rear wall of the installation frame, mates with the single connector on the rear plate of the storage array module housing and is connected to an external connector on the rear wall of the installation chamber. It will be readily apparent to those of ordinary skill in the art that different types and quantities of connectors may be used to provide the necessary connections. Also, the connectors can be placed at any locations that are convenient to other installation requirements. For example, the connectors can be located at the front of the module.
A plurality of resilient mounts are fastened to external surfaces, for example, on the side walls, of the installation frame to protect the frame and storage array module from external shock when the installation frame is mounted to a supporting platform. A thermal transfer mechanism transfers thermal energy between the electronic units and a region exterior to the installation frame.
In an optional but preferred form of this embodiment, a guide mount includes first slotted rails on the exterior of the side walls of the array housing and second slotted rails on the interior of the side walls of the installation frame such that the first and second slotted rails nest to support the array housing in the installation frame. Optionally, a cam lock in the slot formed by the nested rails rigidly fastens the array housing to the installation frame.
In one form of the thermal transfer mechanism, ventilation units, such as fans, extend through the rear wall of the installation frame, and heat transfer fins on the side walls of the array module housing dissipate heat to the ventilation units. In another form of the thermal transfer mechanism, a plurality of resilient thermal conductors have a first end permanently mounted to respective side walls of the installation frame, and thermal rails are permanently mounted to second ends of the resilient thermal conductors, the thermal rails being mounted to an external heat sink.
In a second embodiment of the present invention, an electronic unit, such as a disk drive, is enclosed in a chamber formed by at least a top cover and a bottom cover hermetically sealed to the top cover. A connector, which can be a blind-mate connector, on one of the covers mates with a connector on the electronic unit. The electronic unit has at least two side rails rigidly fastened to the unit, and a resilient support connects these side rails to at least one of the covers to resiliently support the electronic unit in the enclosure. The resilient support typically is formed of a material having a high resistance to thermal conduction. In such a case, at least two thermal rails are permanently mounted by a plurality of resilient thermal conductors to either the side rails or one of the covers. A fastener removably mounts the thermal rails to the other of the side rails or one of the covers so that the thermal rails and resilient thermal conductors provide conduction of thermal energy between the side rails and one of the covers. If thermally conductive resilient supports are provided, then these thermal conductors are not required.
In this embodiment of the invention, the enclosure may optionally include at least two mounting plates mounted to one of the covers, and the thermal conductors are permanently mounted to the side rails so that the fastener mounts the thermal rails to the mounting plates. In this form of the invention, the resilient support comprises resilient members of various possible shapes, such as bumpers, mounted between the respective side rails and respective mounting plates. Alternatively, the resilient support comprises a molded resilient isolator between the electronic unit and at least one of the covers to support the electronic unit in the enclosure.
In one form of the invention, electronic units fitted with the resilient members and heat transfer mechanisms of the second embodiment are arranged in the array module of the first embodiment.